Re: [linux-lvm] Replace Drive in RAID6

[Heinz Mauelshagen <heinzm@redhat.com>]

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Erm, s/lvchange --repair/lvconvert --repair/

On Tue, Nov 16, 2021 at 6:41 PM Heinz Mauelshagen <heinzm@redhat.com> wrote:

> On Mon, Nov 8, 2021 at 8:08 AM Adam Puleo <adam.puleo@icloud.com> wrote:
>
>> Hello Everyone,
>>
>
> Hi,
> for starters, which kernel/distro is this?
>
> Also, all layout changes on RaidLVs require activated ones.
>
>
>
>>
>> Since the sub-LV #0 has errored, LVM will not let me activate the logical
>> volume.
>>
>> Is there a way to remap the #0 sub-LV to the replaced disk or resizing
>> the RAID6 to one less disk?
>>
>
> Each of the RAID6 SubLV pairs has an internal id and all data and parity
> (P+Q syndromes) have been stored in a rotating pattern  >  no to the
> remapping part.
>
> Also no to the resize, as it'd need a fully operational radi6, thus
> repairing the RaidLV is needed.
>
> As mentioned, '"lvchange --rebuild ..." is inadequate to repair RaidLVs
> with broken/lost PVs, "lvchange --repair $RaidLV" is.
>
> In order to diagnose why your raid6 LV now fails to activate via "lvchange
> -ay --activationmode degraded $RaidLV" which is the proper way to go about
> it,
> can you please describe any/all updating steps you took after the drive
> failed rendering your raid6 LV degraded?  Please don't change anything
> until you made
> that transparent so that we keep chances to fix this...
>
> FYI:
> "lvconvert --(repair|replace) ..." difference is the former repairing
> RaidLVs with failed PVs by allocating space on different, accessible PVs
> hence causing the RaidLV to become fully operational after rebuilding all
> missing block content by using parity stored on the remaining rimage SubLVs
> vs. the latter allowing to replace mappings to intact PVs by remapping the
> RAID SubLV pair to different ones (e.g. faster or less contended PVs).
>
> Thanks,
> Heinz
>
>
>
>>
>> Thank you,
>> -Adam
>>
>>
>> On Nov 4, 2021, at 7:21 PM, Adam Puleo <adam.puleo@icloud.com> wrote:
>>
>> Hello Andreas,
>>
>> After deactivating each of the individual rmage and rmeta volumes I
>> receive this error:
>> # lvchange -a y --activationmode degraded vg_data/lv_data
>>  device-mapper: reload ioctl on  (253:12) failed: Invalid argument
>>
>> In messages I see the following errors:
>> Nov  4 19:19:43 nas kernel: device-mapper: raid: Failed to read
>> superblock of device at position 0
>> Nov  4 19:19:43 nas kernel: device-mapper: raid: New device injected into
>> existing raid set without 'delta_disks' or 'rebuild' parameter specified
>> Nov  4 19:19:43 nas kernel: device-mapper: table: 253:12: raid: Unable to
>> assemble array: Invalid superblocks
>> Nov  4 19:19:43 nas kernel: device-mapper: ioctl: error adding target to
>> table
>>
>> Am I not adding the new drive to the RAID correctly? I first did a
>> pvcreate and then a vgextend.
>>
>> I was using the —rebuild option because I know which physical drive is
>> bad. In the lvmraid man page it says —repair might not know which is the
>> correct block to use so to use —rebuild.
>>
>> Thank you,
>> -Adam
>>
>>
>>
>> On Nov 3, 2021, at 7:25 AM, Andreas Schrägle <linux-lvm@ajs124.de> wrote:
>>
>> On Tue, 2 Nov 2021 22:56:18 -0700
>> Adam Puleo <adam.puleo@icloud.com> wrote:
>>
>> > Hello,
>> >
>> > One of my drives failed in my RAID6 and I’m trying to replace it
>> without success.
>> >
>> > I’m trying to rebuild the failed drive (/dev/sda): lvchange --rebuild
>> /dev/sda vg_data
>> >
>> > But I’m receiving the error: vg_data/lv_data must be active to perform
>> this operation.
>> >
>> > I have tried to activate the logical volume without success.
>> >
>> > How do I go about activating the volume so that I can rebuild the
>> failed drive?
>> >
>> > Thanks,
>> > -Adam
>> >
>> > # lvs -a -o name,segtype,devices
>> > LV                       Type   Devices
>>
>> > lv_data                  raid6
>> lv_data_rimage_0(0),lv_data_rimage_1(0),lv_data_rimage_2(0),lv_data_rimage_3(0),lv_data_rimage_4(0)
>> > [lv_data_rimage_0]       error
>>
>> > [lv_data_rimage_1]       linear /dev/sdc1(1)
>>
>> > [lv_data_rimage_2]       linear /dev/sdb1(1)
>>
>> > [lv_data_rimage_3]       linear /dev/sdf1(1)
>>
>> > [lv_data_rimage_4]       linear /dev/sde1(2)
>>
>> > [lv_data_rmeta_0]        error
>>
>> > [lv_data_rmeta_1]        linear /dev/sdc1(0)
>>
>> > [lv_data_rmeta_2]        linear /dev/sdb1(0)
>>
>> > [lv_data_rmeta_3]        linear /dev/sdf1(0)
>>
>> > [lv_data_rmeta_4]        linear /dev/sde1(0)
>>
>> >
>> > # lvs -a
>> > LV                       VG            Attr       LSize   Pool Origin
>> Data%  Meta%  Move Log Cpy%Sync Convert
>> > lv_data                  vg_data       rwi---r--- 990.00g
>>
>> > [lv_data_rimage_0]       vg_data       vwi-a-r-r- 330.00g
>>
>> > [lv_data_rimage_1]       vg_data       Iwi-a-r-r- 330.00g
>>
>> > [lv_data_rimage_2]       vg_data       Iwi-a-r-r- 330.00g
>>
>> > [lv_data_rimage_3]       vg_data       Iwi-a-r-r- 330.00g
>>
>> > [lv_data_rimage_4]       vg_data       Iwi-a-r-r- 330.00g
>>
>> > [lv_data_rmeta_0]        vg_data       ewi-a-r-r-   4.00m
>>
>> > [lv_data_rmeta_1]        vg_data       ewi-a-r-r-   4.00m
>>
>> > [lv_data_rmeta_2]        vg_data       ewi-a-r-r-   4.00m
>>
>> > [lv_data_rmeta_3]        vg_data       ewi-a-r-r-   4.00m
>>
>> > [lv_data_rmeta_4]        vg_data       ewi-a-r-r-   4.00m
>>
>> >
>> >
>> >
>> > _______________________________________________
>> > linux-lvm mailing list
>> > linux-lvm@redhat.com
>> > https://listman.redhat.com/mailman/listinfo/linux-lvm
>> > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>> Hello Adam,
>>
>> how exactly have you tried to activate the LV so far?
>>
>> lvchange with --activationmode degraded should work, no?
>>
>> Also, are you sure that --rebuild is the correct operation?
>>
>> man 7 lvmraid suggest you might want --repair or --replace instead.
>>
>> Best Regards
>>
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://listman.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://listman.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
>>
>> _______________________________________________
>> linux-lvm mailing list
>> linux-lvm@redhat.com
>> https://listman.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>
>

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